This invention is related to a system for initially guiding flying missiles toward a target. More particularly, the invention relates to an initial guidance system that utilizes laser light which is scattered from aerosol particles that are naturally present in the atmosphere onto light: detectors on the missile to generate guidance signals.
When a missile with a terminal homing seeker (ex. Thermal Imaging Seeker, Hot Spot Infrared Seeker, Laser Semi-Active Seeker, Millimeter Wave Seeker, or other) is first launched, initially there may be inadequate target signature to enable the homing seeker to lock onto the target. When such as the situation, the terminal homing seeker must be supplemented with initial guidance which can guide the missile in the general direction of the target until the homing seeker can take over, using more abundant target signature as the missile gets closer to the target. One way to supply this initial guidance is to place sufficient computational power and intelligent algorithms (Smart Missile) on board to enable the missile independently to lock onto the target at the time of launch. However, this is a difficult and expensive approach. Another way is to use dual mode guidance, such as conventional laser beamrider guidance during the initial flight, with terminal homing when the missile is sufficiently near the target. Dual mode guidance entails lower risk technically but is complex and also expensive.
A laser beamrider system for initial missile guidance has been previously contemplated. See, Statutory Invention Registration No. H796 on which Walter E. Miller, Jr. is a named co-inventor as he is on instant application. The system described in SIR H796 is extremely complex in spite of efforts to simplify the beamrider guidance functions and hardware. The complexity stems from having two fully capable guidance links, which essentially doubles the number of guidance functions employed. What is needed is a less complex mechanism for the initial guidance. Such initial guidance need not be extremely accurate, but should be simple and relatively inexpensive to implement. The present invention provides such a guidance system.